"This is really going to change the way in which we address development," Angel Gurria, secretary-general of the Organization for Economic Co-operation and Development, told reporters.
He said the adoption of a multi-year action plan would be a "a very big deliverable" from the two-day G20 summit, which starts on Thursday.
The blueprint identifies nine areas where action is needed to ease development bottlenecks, including skills training, increased access to finance, expanded investment and improvements to the physical fabric of developing countries.
"The great leap forward here is that this is no longer a question of aid. It's a question of development," Gurria said.
Gurria applauded summit host South Korea for driving the new agenda, which says there is no one formula for development success.
Central bank governor Kim Choong-soo said South Korea's graduation from aid recipient to donor added credibility to the strategy.
German Chancellor Angela Merkel backed the plan as a step toward market-orientated growth. "We must quit the traditional path of development aid," she told business leaders.